Metal severing apparatus



Feb. 11, 1947. w s KMGHT HAL 2,415,746

METAL SEVERING APPARATUS Filed Jan. 24, 1945 2 Sheets-Sheet 1 INVENTORSZ W44 me 4 Feb. 11 1947. w s, KMGHT ETAL 2,415,746

METAL SEVERING APPARATUS Filed Jan. 24, 1945 2 Sheets-Sheet 2 Patented Feb. 11, 19 47 :s'rA'rEs METAL SEVERING APPARATUS Application January 24, 1945, Serial No. 574,418

This invention relates to severing or cutting off tools fo metallic workpieces such as pipes, bars and the like,- and to cutting-off machines, including lathes, wherein large numbers of workpieces which are to be used for ordinary commercial purposes are cut.

Conventional cutting-off tools are formed. from bars of hardened tool steels which are rigidly held in heavy tool holders. It is frequently necessary to remove the tools from their holders in order to sharpen them or remove broken edges caused by uneven or crooked workpieces. Proper adjustment thereof is diiiicult and particularly so when a plurality of cutting tools are used in a single head so; that the work is divided therebetween.

It is accordingly an object of the present invention to provide metal severing apparatus wherein the relative distance between the work and the cutting faces is not disturbed by removing the cutters for sharpening.

It is a further object of the present invention to provide metal severing apparatus that is economical to operate and rugged and simple in design.

The foregoing and further objects will be apparent from the specification and drawings wherein:

Figure 1 is a plan view; Figure 2 is an end view;

Figure 3 is a cross section along the lines 111- III of Figure 2;

Figure 4 is an enlarged end view of the cutting tool of our invention showing the disposition of the cutting edge with respect to a workpiece; and

Figure 5 is an enlarged plan of the cutting tool, partly in section, showing the reliefs provided therein.

Referring more particularly to the drawings, the numeral 2 designates a conventional form of motor-driven rotatable spindle having a clutch controlled cam-operated chuck 6 adapted to grip a workpiece such as a length of pipe indicated by the letter W. Since the work-rotating spindle and chuck are of conventional form, they will not be further illustrated or described.

A longitudinallyextending supporting frame 6 is mounted on and anchored to a suitable foundation. A face plate 8 having an opening Ill therethrough, is mounted on the frame by a support l2. The face plate 8 has a central rearwardly extending bearing portion M on which .there is rotatively mounted between the face plate 8 and support i2, a cam plate i6. Slidably mounted on 7 Claims. c1. lei-:69)

the face plate 8 on holders H8 in slideways 20 are :three cutting tools 22.

The cutters 22 are positioned in their respective slideways 20 by pins 24 extending outwardly from J both sides of the'face plate 8. so that one end rigidly engages tool holders I8 and the other slidably. engages slots 25 in cam plate Hi. The

slots 25 which are disposed'rearwardly of the tool holders it, are arcuately shaped and have a spiral-like or eccentric disposition so that one end is nearer the opening 10 than the other end, Accordingly, it is seen that a partial rotation of the cam plate [6 will cause the tool holders I8 and cutting tools 22 held thereby to move toward or away from the axis or center of the face plate 8. Cam plate "I6 is provided with means for partially rotating it, such as, a handle member '28.

The cutting tools 22 are generally circular in shape and have a segment removed therefrom to form a cutting edge which engages the workpiece W to remove metal therefrom when it is rotated.

It is advisable to set the center of a disc tool above the center of the workpiece and also to cut above the center of the workpiece. A line drawn through center of the tool and cutting edge of the tool should pass below the center of the workpiece. "This setting provides clearance back of the cutting edge. As shown in Figure 5, tools 22 are mounted at a slight angle a to the blocks. E8 in a plane normal to the cutting edge 30 which provides clearance along the line L-L on the outer face A of the tools. Clearance is provided on the inner face B along the line LL by dishing this face to make it slightly concave, as shown in Figure 5. Heel clearance at point C wherethe tool leaves the workpiece is provided, in addition to the concavity of face B and the angular mounting, by slightly tapering the disc from the cutting. edge 30 to at least point D, which is as far as the disc can'be ground back to form successive cutting edges.

Serrated meeting faces 32 are provided on the studs Stand 34', integral with block l8 and cutters 22, respectively, to hold the cutters against rotation and at the same time make them readily adjustable. The angle a. is preferably provided by making the serrations on the cutter stud 34' parallel to the outer face A while .the serrations on the block stud 34 are cut at'the desired small angle. Due to the angular setting being provided in this manner, point L on face A maintains the same position after the cutting edge is 7 sa s ground back and the disc 22 rotated'relative to the stud as and block is to-bring the cutting edge into the plane it occupied prior to By way of example a 4' circular cutting tool contains about 101 2" of cutting edge and about 9 to 9%" of this edge or 90%, is usable before it is necessary to discard the tools Such a tool has a minimum'overhan'g at the-cutting edge and a greater depth of beam at the critlcaljoint of support. This is a source of strength resulting in this type of tool being less subject to breakage than conventionalba'r tools.

By providing edge and heel clearances or reliefs in the aioredescribed manner, the disc thick ness is changed very-slightly, permitting it to be ground back to form successive cutting edges until practically 'all of thedisc has been so used. Also, one of the more important advantages of so providing clearance and relief is that when" two or more of such tools are mountedin gang to cut in the same groove, it is not necessary to grind each disc exactly the same amount in sharpening as the thickness change is so gradual. Thus, if due to eccentricity of the workpiece the.

. edgeof one tool becomes broken, it is not necessary to grind back the others but only the one that needs re-edging; Moreover, since the point L on face A remains constant, autoinatic positioning or measuring devices, such as targets or stops, beyond the tool may be used and the length of thepiece being cut is not affected by grinding of the disc to form new cutting edges.

As above pointed out with such tools, the holders can be-adjusted with respect to each other and thereafter when the tools are removed for sharpening, it'is not necessary to readjust them as the cutting edge remains a constant distance from the mounting hole in the center of the disc.

While we have shown and described one specific embodiment of our invention, it will be pass said stock while held by said rotating means, a plurality ofslide blocks slidably mounted on said support for movement radially of the longitudinal axis of said stock, severing tools adiust- .ably mounted on said slide blocks, each of said severing tools comprising a disc havings, se ment removed therefrom to form a cutting edge, said disc beingfmountedj on a slide block at a) slight angle to said support in a plane through said cuttingedge to provide clearance for one, side of said cutting edge, the opposite side of said disc being slightly concave to provide clearance for the other side of said cutting edge, and

understood that this embodiment is merely for the purpose of illustration and description and that various other forms may be devised within the scope of our invention, as defined in the appended claims.

We claim:

1. A tool for severing metallic articles com- 7 prising a holder,- a severing tool adjustably mounted on said holder,.said severing tool comdisc having a segment removed therefrom to form a cutting edge, said tool being mounted on said holder at a slight angle thereto in a plane through said cutting edge to provide clearance for one side of said cutting edge, the opposite side of said disc being slightly concave to provide clearance for the other side of said cutting edge, said disc being tapered to reduce the thickness thereof rearwardly from said cutting edge to provide edge clearance between said disc and work being cut thereby below said cutting edge.

3. A machine tool for severing elongated bar or pipe stock, comprising means for rotating the stock on its longitudinal axis, a tool supp rt having in opening therethrough adapted to encommeans for moving said blocks radially of said stock. I

4. A machine tool for severing elongated bar or pipe stock, comprising means-tor rotating the a stock on its longitudinal axis, a tool support having an opening therethrough adapted to encompass said stock while held by said rotating means, aplurality of slide blocks slidably mounted on said support for movement radially of the longitudlnaiaxis of said stock; severing tools adjustably mounted on said slide blocks, each of said severing tools comprising a disc having a segment removed therefrom to form a cutting edge, said disc being mountedon a slide block at a slight angle to, said support in. a plane through said cutting edge to provide clearance for one side of said cutting edge, the opposite side of said disc being slightly concave to provide clearonce for the other side of said cutting edge, said disc being tapered to reduce the thickness thereof rearwardly from said cutting edge to provide heel clearance between said disc and work being cut thereby. 1

5. A tool for severing metallic articles comprising a holder, adisc carried by said holder, said disc having a segment removed therefrom to fbrma cutting edge, means for adjustably mounting said disc on said holder, said adjustable mounting means including serrated meeting faces between said holderand said disc, the meeting face on said disc being parallel to theouter face of the disc, the meeting face of the holder being angularly disposed with respect to the axis of rotation of the disc in a longitudinal plane along the axis of said disc intersecting the cutting edge, the plane of said holder serrations and the plane of said outer face intersecting along a line on the opposite side of said disc from the cutting edge whereby clearance is provided along said face, the opposite face of said tool being concave.

.6. A tool for severing metallic articles com-- prising a holder, a disc carried by said holder, said disc having a segment removed therefrom to form a cutting edge, means for adiustably mounting said disc on said holder, said adjustable mounting means including serrated meeting faces between said holder and said disc, the meeting face on said disc being parallel to theouter face of the disc, the'meeting face of the holder bein angularly disposed with respect to the axis of rotation of the disc in a longitudinal plane along the axis of said disc intersecting the cutting edge, the plane of'said holder serrations and the plane of said outer iaceintersecting along a line on the opposite side of said disc irom'the cutting edge whereby clearance is provided along said face, the opposite face. of said tool being concave, said tool being peripherally tapered rearwardly' from said cutting edge. V

7. A tool for severing metallic articles comprising a substantially circular disc, said disc having a segment removed to form a cutting edge, one face of said disc being fiat and normal to the axis thereof, the other face of said disc being beveled to reduce the peripheral thickness thereor rearwardly from said cutting edge, said last 5 mentioned surface being concave whereby edge and heel clearance on both faces of said tool is obtained by mounting said tool at a slight angle to the longitudinal axis of a, workpiece in a plane normal to the cutting edge.

WAL'I'ER S. GHT. WALTER A. 7

amass The following references are of record in the file of this patent: 

